This invention relates to topical compositions comprising guanidine compounds and peroxide compounds and processes for the conjoint use of such compounds. More particularly, the invention relates to topical compositions for the treatment of skin lesions and methods for treating skin lesions whereby the irritation commonly produced by peroxide compounds is reduced.
Acne and seborrhea are conditions of the human skin characterized by an excessive flow of sebum, or skin oil, from the sebaceous glands located in the pilosebaceous apparatus. Sebum reaches the skin surface through the duct of the hair follicle. The presence of excessive amounts of sebum in the duct and on the skin acts to block or stagnate the continuous flow of sebum from the follicular duct, thus producing a thickening and a solidification of the sebum to form a solid plug known as a comedone. When this process occurs, hyperkeratinization of the follicular opening is stimulated, thus completely closing the duct. The usual results are papules, pustules, or cysts, often contaminated with bacteria which cause secondary infections. Acne is particularly characterized by the presence of comedones, inflammatory papules, pustules, or cysts. The effect of acne ranges from slight skin irritation and pitting to disfiguring scars.
Many topical therapeutic agents are employed in the treatment of acne and seborrhea to prevent the blocking of the follicular duct, to reopen the duct once it has become blocked, to act against the infecting bacteria or the thickened sebum, and to provide combinations of each of these actions. The horny outer layer of the skin (stratum corneum) is formed of dead cells composed largely of keratin. Therapeutic agents which act to prevent the blocking of the follicular duct by promoting the removal of sluffing off of excess keratin are known as keratolytic agents. Sulfur, resorcinol and salicylic acid have been used as keratolytic agents in the treatment of acne.
For over sixty years, benzoyl peroxide has been used as a keratolytic agent in the topical treatment of skin lesions such as burns, varicose ulcers, sycosis vulgaris, seborrhea, and acne. Benzoyl peroxide, (C.sub.6 H.sub.5 CO).sub.2 O.sub.2, is a colorless, odorless, tasteless, crystalline solid, stable at ordinary room temperatures; it is a powerful oxidizing agent, yet nontoxic to man. As noted, benzoyl peroxide has been used as a very effective keratolytic and antibacterial agent in the treatment of acne. While benzoyl peroxide is an effective topical agent for the treatment of skin lesions such as appear in acne or seborrhea, it has the undesirable side effect of being a contact irritant. Accordingly, some patients are denied the benefits of peroxide acne therapy because of the irritation problem.
It has now been discovered that guanidine compounds used in conjunction with a peroxide compound will reduce the skin irritation caused by the peroxide compound.